Sound-box for talking-machines.



B. L. RINEHART.

SOUND BOX FOE TALKING MACHINES.

Patented June 4, 1912.

APPLICATION FILED JAE. 29, 1906.

llllllll ullul lessees.

UNITED STATES PAinlrw r us BENTLEY r... museum, or cannon, new Jiznsnz, 'assronon T vxc'ron TALKIN; umcnmu continuity, A conrons'rron or new muses.

SOUND-BOX For. TALKINGIMACIENES'.

rater-ea June 4, leis.

Application filed January 29, 123%. fserial Re. 288,339.

plete disclosure, referenee being bad i) the accompanying drawings, formmg'part of this specification.

The main objects ofthis invention are to provide in a sound box, an improved mounting for a diaphragm; to provide a sound box having a diaphragm, in which the diaphragm may be readily removed and replaced without injury thereto; and to prothe cylindrical wall of the groove.

vide' other improvements as Wlll appear 1 hereinafter.

, v In. the drawin Figurel is alongitudinal central seption' o a sound box constructed in accordance'with this invention; Fig. 2 on enlarged "fragmentary portion of the and Fig. 3 a front elevation of the diaphragm and its supporting ring.

Referring to the drawings, the improved sound comprises an annular casing 1 having a cylindrical bore opening in the face thereof. The usual rubber tubular e2;- tension 2 is secured to the back of the 021s ing, andwithin this extension is a tubular lining 3 communicating with the interior of the casing, whereby the sound box may be telescoped over the usual tubular support. usual diaphragm is mounted within the bore of the casing and is phonetically connected in any suitable manner to the stylus bar 5 which is mounted upon the eas ing in a Well known manner to oscillate in a plane perpendicular to the diaphragm.

The diaphragm d is supported within and by a yielding ring 6 preferably made of soft rubber or other resilient material. This ring is externally cylindrical and tits snugly in the cylindrical bore of the casing, being irictionally retained in place. The interior surface of the ring is provided with an annular groove or circumferential depression, having inclined conical side Walls 7-7 connected by a cylindrical wall. The periphery of the diaphragm rests within this groove, the cylindrical surface or Wall otthe periphery of the diaphragm bearing aga ilnfit e conical side Walls of. the groove are tangent to the edges of the diaphragm and the sides or flat faces of the diaphragm are out of contact with an part of the ring or sound box casing, the aces of the diaphragm being tree to flex throughout their entire areas. The diaphragm is thus permitted-to respond readily to theaction of the sound Waves or to the oscillation of the stylus bar. v

The yielding rin is expanded into posi tion over the diap ragm before being insorted into the casing, and the shape and dimensions of the ring are such that when the ring is in place over the diaphragm, the ring and diaphragm, as a unit, ma be readily insertedinto, or Withdrawn rom, the sound box casing, through the open end of the bore of the casing The normal diam ter of the interior groove in the ring may be slightly smaller than the diameter of the diaphragm, so as to compress the diaphragm radially through the resiliency of the ring; or the normal diameter of the groove may be of substantially the same diameter as the diameter'of the diaphragm to hold the diaphragm Without exerting any appreciable pressure thereon.

One of the purposes involved in mounting the diaphragm is to support the diaphragm at its periphery or circumferential wall only, and this purpose may be realized by using the grooved'ring as described, or the ring might be omitted, and other similar means substituted for accomplishing the same end. The shape of the ring may be varied from that described'or the'ring may be made integral with the sound box casing instead of detachable therefrom, the yielding quality of the ring serving to permitof the lIlSEltion or removal of the diaphragm.

This invention has been illustrated only in its preferred form, but various changes, some or which have been suggested above, may be made inthe construction. shown" without departing from too spirit of this invention, or the scope of the appended claims.

Having thus described my invention, I

claim and desire to protect by Letters Patent of the United States:

1. In a sound box the combination with av casing provided With a cylindrical bore having one end open to the full diameter of the bore, of a solid resilient gasket having a.

cylindrical periphery, said gasket being frictionally and rcmovably retained in said casli t I said gasket with the'cylindrical wall of said hore, and a diaphragm entirely supported by said gasket and having its. opposite plane surfaces out of engagement with said gasket.

2. In a sound box the combination with a casing provided with a cylindrical bore having one end open to the full diameter of the bore, of a solid resilient gasket having'a cylindrical periphery of the same diameter as said bore and frictionally retained in said casing by the engagement between the periphery of said gasket and the cylindrical wall of said bore, said gasket being provided with an internal annular groove having side Walls diverging from the bottom thereof toward the center of said gasket, said diaphragm being supported by said gasket by the frictional engagement of the circumferential edge of said diaphragm with the walls of said groove.

In witness whereof I have hereunto set my hand this 26th day of January, 1906.

BENTLEY .L. RINEHART. Witnesses:

WM. EARL, CHAS. K. BENNETT. 

